The invention concerns a roof for a motor vehicle and, in particular, a vehicle roof for a passenger motor vehicle with at least one roof panel element and with at least one lining element by which the roof element is at least partially lined towards a passenger compartment of the motor vehicle.
DE 101 63 822 B4 discloses a roof module for a motor vehicle which is provided for mounting between side parts of a passenger compartment below a roof skin extending between longitudinal pillars of the side parts. On a roof module's side facing the passenger compartment of the motor vehicle an energy absorption element in the form of a foam material is disposed.
From DE 10 2005 026 237 A1 a vehicle roof ceiling arrangement is known. The roof ceiling arrangement includes a main body by means of which a roof of the vehicle is at least partially lined towards a passenger compartment of the vehicle. Therein, in an intermediate space between the roof and the main body, a foam element is disposed.
Finally, from DE 10 2005 015 203 A1 a vehicle roof with a roof skin as a roof element and with a lining shell as a lining element is known. By means of the lining element, the roof element is at least partially lined towards a passenger compartment. The lining element is, with the formation of an intermediate space between the roof element and the lining element, spaced from the roof element.
In the intermediate space an air-conveying duct is provided, which in the case of a head impact on the lining element is supposed to absorb the impact energy. The air-conveying duct therefore acts as an energy absorption element which is coupled to the lining element and which at least partially decelerates a motor vehicle occupant impacting the energy absorption element at least indirectly during an accident-related application of force.
The known energy absorption elements, in particular, those in the form of foam elements, have a very high need for space. In addition, the accident behavior of the known vehicle roofs deserves improvement.
It is thus an object of the invention to further develop a motor vehicle roof of the type stated in the introduction in such a manner that improved accident behavior as well as lower need for space by the absorption element are provided.
This and other objects are achieved by a motor a vehicle roof for a passenger motor vehicle with at least one roof panel element and with at least one lining element by which the roof element is at least partially lined towards a passenger compartment of the motor vehicle. At least one energy absorption element is coupled to the lining element for the at least partial deceleration of an occupant impacting the energy absorption element at least indirectly during an accident-related application for force, and is characterized in that the energy absorption element is formed as an essentially flat plate element.
Such a roof for a motor vehicle according to the invention, in particular a passenger motor vehicle, comprises at least one roof element and at least one lining element. Therein the roof element is, by way of the lining element, at least partially lined toward a passenger compartment of the motor vehicle. Furthermore, there is provided, coupled to the lining element, at least one energy absorption element by which an occupant in the passenger compartment is to be decelerated if said occupant impacts the energy absorption element at least indirectly during an accident-related application of force.
To realize an improved accident behavior as well as a low need for space of the energy absorption element it is provided according to the invention that the energy absorption element is formed as an essentially flat plate element. The plate element can, in case of an impact of the head of the occupant, decelerate the head without leading to undesirably high acceleration values. Thereby the vehicle occupant can be protected against serious injuries.
Along with this, it is provided that, for at least partial deceleration of the occupant, in particular her/his head, upon its at least indirectly impacting the plate element, opposing impetuses can be applied to the occupant or her/his head by means of the plate element through back-and-forth springing of the plate element. In other words, if the head of the occupant strikes the plate element at least indirectly, e.g. with the intermediation of the lining element, then an acceleration of the plate element occurs which is briefly greater than an accident-related acceleration of the head. The plate element springs initially away from the head, in particular the lining element, and subsequently as a consequence of the coupling to the lining element once again onto the head. This sequence of events occurs in only a very short amount of time and is repeated many times over a very short period of time so that the plate element springs back and forth (or swings back and forth) for a very short time strikes the head at least indirectly, e.g. with intermediation of the lining element, and thereby applies opposing impetuses to the occupant or her/his head.
In this process, the opposing impetuses at least essentially oppose the accident-related acceleration and, accompanying it, an accident-related displacement of the occupant or her/his head so that the accident-related acceleration of the head shortly decreases and the occupant or her/his head is decelerated by the swinging back and forth of the plate element. In connection with this, the flat design leads to a plate element rigidity behavior and weight advantageous for applying the opposing impetuses.
The deceleration of the head as well as a path for the head to press into the plate element depend in particular on the modulus of elasticity of the plate element. By an appropriate setting of the modulus of elasticity, the accident behavior of the plate element can be set as needed. At the same time, the principle of action of the plate element is based above all on the modulus of elasticity at the moment of a flexure of the plate element as a consequence of the at least indirect impact of the head, on the weight of the plate element, and on the law of conservation of momentum, e.g. in cooperation with bonding of the plate element and lining element over a large surface. In connection with this, the plate element can briefly accelerate more rapidly than the head.
In an advantageous embodiment of the invention, the plate element lies at least partially on the lining element, in particular over an at least predominant area of its surface extension. Through this lying on the surface, tensile forces arise which lead to a particularly advantageous and rapid back-and-forth springing of the plate element so that the occupant can be decelerated very well.
It has been shown to be particularly advantageous if the plate element is spaced, in particular completely, from the roof element. Therefore no coupling to and/or other support of the plate element on the roof element is provided so that the plate element can spring back and forth unhindered and apply opposing impetuses to the occupants.
A particularly advantageous, since essentially unhindered, swinging back and forth of the plate element is provided if the plate element is disposed in an intermediate space bounded on one side by the roof element and on the other side by the lining element with spacing from the roof element.
In an advantageous development of the invention, a rib structure is provided by which the plate element is reinforced. The rib structure lends a high modulus of elasticity to the plate element so that it has high elasticity and, as a consequence, very good back-and-forth springing and opposing impetuses for decelerating the occupant or her/his head which it can apply to them.
It has been shown to be advantageous if the rib structure extends at least over a predominant part of a surface, e.g. in the form of a broadside, of the plate element. The plate element is thus reinforced over a large surface area and has very good spring behavior.
In order to keep the number of parts and the costs of the vehicle roof low, the rib structure and the plate element are preferably formed as one piece with one another. The rib structure is formed, for example, in the framework of an initial forming process and/or a reforming process to produce the plate element.
The vehicle roof is furthermore distinguished in that the plate element is made of a metallic material, in particular of sheet steel. Thus, the plate element has a corresponding modulus of elasticity as a consequence of which the plate element can spring back and forth in only a short time and as a consequence can decelerate the occupant very well.
In an additional embodiment, it is provided that the plate element is formed of plastic, whereby a low weight of the plate element is realized.
Moreover it has been shown to be advantageous if the plate element is disposed on the lining element and lies over the surface of the lining element's side facing away from the passenger compartment. The plate element is thus covered over by the lining element and cannot be perceived visually by the occupant. Furthermore, lying over the surface leads to a very good back-and-forth springing.
In connection with this, the plate element can be disposed on an external rear side of the lining element, said rear side facing away from the passenger compartment. Similarly, it is possible that the plate element is disposed within the lining element. In connection with this, the lining element can comprise a receiving space in which the plate element is disposed. In other words, the plate element is not disposed on a side facing the passenger compartment but rather on the side facing away from the passenger compartment and is covered over towards the passenger compartment by the lining element.
In order to provide a connection of the plate element to the lining element, in a further development of the invention, it is provided that the plate element is glued to the lining element. This glued connection is particularly favorable from the standpoint of weight. In so doing, it can be provided that the lining element and the plate element are glued to one another over a complete surface area on which they lie on one another. Through the gluing over a large surface area, very high tensile forces act which cause a very good swinging behavior of the plate element so that it swings back and forth frequently in only a very short time, impacts the head at least indirectly, and decelerates it.
Additional advantages, features, and details of the invention follow from the following description of preferred embodiment examples as well as with the aid of the drawings. The features and combinations of features stated above in the description as well as the features and combinations of features stated below in the figure description and/or shown only in the figures are not only usable in the combination specified in each case but rather also in other combinations or alone without leaving the scope of the invention.